Compressor



Dec. 29, 1942 E. KING 2,306,813

7 COMPRESSOR I Filed Sept. 16, 1941 Inventor: Ralph E. King,

His AttoTney' Patented Dec. 29, 19 42 COMPRESSOR Ralph E. King, FortWayne, Ind., assignor to General Electric Company, a corporation of NewYork Application September 16, 1941, Serial No. 411,036

6 Claims.

My invention relates to compressors and particularly to compressorsprovided with devices for separating oil from the working fluid admittedto the compressor.

Compressors operating in systems such as refrigerating machines whichhave closed circuits tl.rough which the'working fluid is circulatedunavoidably entrain small quantities of the lubricating oil in theworking fluid. In order to mainscription proceeds, and the features ofnovelty whichcharacterize my invention will be pointed out withparticularity in the claims annexed to and forming a part of thisspecification.

For a better understanding of my invention reference may be had to theaccompanying drawing in which Fig. 1 shows a partial elevational view insection of a refrigerant compressor embodying my invention; and Fig. 2is 1 a diagrammatic view of the compressor of Fig. 1

arranged in a refrigerating system.

Briefly, the compressor shown in the drawing comprises a cylinder blockhaving a reciprocat ing piston mounted therein and a crankcase forholding a quantity. of lubricating oil. The 28. Thehead 2| has formedtherein acha'mber compressor is provided with a valve plate and 29 aboutthe intake port Manda second cham a head providing the intake andexhaust pasber 30 separated from the chamber 295 by a sages and valvesfor the compressor cylinder wall 3| and communicating with the -chamberin which the piston is mounted. In order to 29 through a restrictedopening 32 in the wall I 3|. The chamber 30 is arranged'toreceive-workseparate oil from the working fluid drawn into compressortwo parallel paths are provided between the suction connection of thecompressor-and the intake port of the cylinder. An oil separatingchamber is arranged at the entrance of the two chambers and one path.leads directly to a chamber at the intake port of the compressor whilethe other leads through the crankcase. Most of the oil separated fromthe working fluid is directed so that it flowsthrough the path leadingthrough the crankcase and the oil is trapped and retained in thecrankcase while the working fluid flows to the intake port.

Referring now to the drawing,'the compressor shown in Fig. 1 comprises ablock l0 having tain the desired quantity of lubricant in the acrankcase ll formed integra y therewithcompressor crankcase and also toprevent lower- Only a portion of the crankcase has been shown ing of theeffective capacity of the working in Fig. 1. However, its outline isindicated in fluid, it is necessary to separate the lubricant Fig. 2 andits construction is in accordance with from the working fluid and returnit to the well-known practice. A cylinder I2 is formed in crankcase.Many different arrangements have the block l0 and a ecip o a piston orbeen provided for this purpose. 7 placement member I3 is mountedtherein. The It is an object of my invention to provide a. piston isactuated by rotation of a shaft I4 driven compressor having an improvedarrangement for by a su table motor (not Shown) ou a Crank separatingand returning to the crankcase lubripm Hi and a co n joined to theeating oil which has become entrained in the piston by means of aSuitable Wrist-Din working fluid returned to the compressor.counterweight I8' is provided to balance the Another object of myinvention is to provide compressor and a splashing'element or finger ISa compressor having an improved oil return is secured. to thecounterweight to dip into a device of simple and rugged constructionwhich body of oil in the bottom of the crankcase and may be arrangedentirely within the compressor splash oil to the working parts of themechaand is effective to return to the crankcase a nism. The shaft I l,as shown in the drawing, high proportion of the lubricating oil enteringis intended to be rotated in a counterclockwise the compressor intakewith the working fluid. direction. The counterweight l8 and the fingerFurther objects and advantages of my inven- 19 are displaced axially tothe rear of the contion will become apparent as the following denectingrod, as viewed in Fig. 1, so that they can- 'not strike the walls of thecylinder l2. The

compressor is provided with a valve plate 20 and a head 2|. Gaskets22-are provided on either side of the valve plate, and thehad and valveplate are secured to the block by a plurality of cap screws 23. Thevalve plate'is provided with an intake port 24. and an intake valve 25of the flexible 'reed type is securely held between the plate and theblock to; control the port 24. Suitable pins 26 may befemplcyed toposition the valve 25 securely. An"'exh'aus't port 21 is formed in thevalve plate 20 i'nc'olnmunication with the cylinder li a'rld iscontrolled by a suitable exhaust valve indicated at suction connectionbeing provided with a suitable fine mesh wire screen or filter topreventforeign matter fromentering thetcompressor. The head 2| is providedwithan ex haust chamber 35 in communication with the exhaust port 21.and arranged to discharge working fluid from the compressor through anexhaust passage 36 in an exhaust or discharge connection 31.

The arrangement of the chamber 30 and the restricted opening 32 is suchthat considerable turbulence of the working fluid drawn into thecompressor occurs in the chamber 30 and lubricating oil entrained in theworking fluid is separated and falls to the bottom of the chamber. Thislubricant may be returned to the crankcase through a suitable duct 38formed in the block l and in the plate 20. In order to cause a positiveflow downwardlv through the duct 38, I provide a second duct 39 in theblock "I and valve plate 20 in communication with the chamber 29 at itsupper end and with the crankcase at its lower end. A suitable tube 40may be inserted in the lower end of the duct 39 and the end thereof benttoward the side of the crankcase so that its open end, indicated at 4|,is in the same direction as the direction of movement of the splashingelement l9, and the tendency of oil to be splashed into the opening 4|is minimized. The extension tube 40 is not, however, necessary to thesatisfactory separation of the oil from the gaseous refrigerant enteringthe cylinder.

The duct 39 is preferably made of a larger cross-sectional area than theduct38 to facilitate the drawing of working fluid through the duct 33into the crankcase and thence into the duct 39 to the chamber 29. Thisprovides a parallel path for the flow of gaseous working fluid from thesuction connection 33 to the chamber 29. Most of the working fluid flowsfrom the connection 33-to the chamber 29 through the chambers 29 and 30and the opening 32 in series communication. The positive flow of fluidthrough the duct 38 draws into the crankcase the lubricant separatedfrom the working fluid in the chamber 30 This lubricant is trapped inthe crankcase while the working fluid .flows from the crankcase to thechamber 29 through the duct 39. This construction provides a'simple andeffective device for separating lubricant from the working fluidadmitted to the compressor and ing svstem as indicated in Fig. 2. Thedischarge connection 31 is secured to a connector 42 of a discharge lineby which the hot compressed refri erant is conduc ed to a condenser 43.The refrigerant in the condenser 43 is cooled and liquefied by operationof a fan 44 driven by an electric mo or 45. and the liquid refrigerantis delivered to a receiver 46. From the receiver 46 the refrigerantflows to an evaporator 41 under the controlof a thermostatic expansionvalve 43 having its thermal element 49 in heat exchange with the outletor suction line 50 of the evaporator. The vaporized refri erant isreturned to the compressor through the suction line 50 which is securedby a suitable connector to the suction connection of the compressor.

During the operation of the'refrigerating system shown in 'Fig. 2 acertain amount of the lubricant in the crankcase l unavoidably entersthe cylinder of the compressor because of the.

pumping action of the piston which forces the oil or lubricant along thecylinder walls, and this lubricant is entrained with the refrigerantdischarged to the condenser and flnds its way to the evaporator andeventually is returned to the compressor intake through the suction line50. The greater part of the lubricant which enters the compressor headwith the refrigerant is separated from the vaporized refrigerant in thechamber 30 of the compressor and flows from the chamber 30 through theduct 38 to the crankcase. The greater portion of the vaporizedrefrigerant flows to the chamber 29 and the intake port 24 throughthe'restricted opening 32, and the portion of the gaseous refrigerantflowing through the crankcase reaches the chamber 29 and the intake port24 through the duct 39.

From the foregoing it is readily apparent that I have provided a simpleand effective arrangement for separating lubricating oil from theworking fluid admitted to the compressor and for returning the oil tothe crankcase. This arrangement requires no additional working parts andno complicated structure and may be built easily into the head of thecompressor.

While I have described my invention in connection with a refrigerantcompressor, other applications will readily be apparent to those skilledin the art. I do not therefore desire my invention to be limited to theparticular construction shown and described, and I intend in theappended'claims to cover all modifications within R the spirit and scopeof my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is:

1. A compressor having a crankcase, working fluid suction and exhaustconnections for said compressor, said compressor having a cylinder and adisplacement member therein, means providing intake and exhaust portsand valves therefor, means providing two parallel paths for the flow ofgaseous working fluid from said suction connection to said intake port,one. of said paths including said crankcase, and means adjacent theinlet of said one of said parallel paths for separating lubricant fromthe working fluid flowing from said suction connection to said paths andfor directing the lubricant into said one path whereby lubricantentrained in the working fluid entering said suction connection isreturned to said crankcase.

2. A compressor having a crankcase, workin fluid suction and exhaustconnections for said compressor, said compressor having a cylinder and adisplacement member therein, means providing an intake port and anexhaust port for said cylinder and valves therefor, means providing afirst chamber adjacent and in communication with said intake port, meansproviding a second chamber between said first chamber and said suctionconnection and a restricted opening between said chambers, meansproviding ducts between said chambers and said crankcase, the ductbetween said flrst chamber and said crankcase having a largercross-sectional area than the duct between said second chamber and saidcrankcase whereby a portion of the working fluid entering said secondchamber flows to said flrst chamber through said crankcase and oilcarried thereby is separated therefrom and retained in said crankcase.

3. A compressor comprising a block having a cylinder and a working fluiddisplacement member therein and a crankcase for holding a body oflubricating 011, said cylinder having intake and exhaust ports, valvesfor said ports, intake and exhaust. connections for said compressor,means providing two chambers connected in series communication betweensaid intake connection and said intake port to provide a. first path forgaseous working fluid flowing from said intake connection to said intakeport, means providing ducts connecting both of said chambers with saidcrankcase to provide a second path for gaseous working fluid flowingfrom said intake connection to said intake port, said paths being soarranged that portion of the gaseous working fluid flow from said intakeconnection through said paths in parallel to said intake port wherebyoil entrained in the portion of the working fluid flowing through saidsecond path is retained in said crankcase.

4. A. compressor comprising a block having a cylinder and a workingfluid displacement member therein and a crankcase for holding a body oflubricating oil, said cylinder having intake and exhaust ports, valvesfor said ports, intake and exhaust connections for said compressor, ahead for said compressor havinga chamber formed therein about saidintake port, means providing communication between said chamber and saidcrankcase, said head having a second chamber formed therein and arrangedin communication with said intake connection and with said firstmentioned chamber for separating oil from the gaseous working fluidflowing from said intake connection to said intake port, means providingcommunication between said second chamber and said crankcase whereby aportion of the gaseous working fluid flowing to said intake port passesto said flrst mentioned chamber through said crankcase and oil separatedfrom the working fluid in said second chamber flows to said crankcaseand is trapped therein.

5. A compressor comprising a cylinder block and a crankcase, saidcylinder block having a cylinderand a reciprocating piston mountedtherein, a valve plate having intake and exhaust ports for saidcylinder, valves for said ports, a head for said compressor havingintake and exhaust con nections, said head having two chambers formedtherein and having a restricted opening providing communication betweensaid chambers one of said chambers being in direct communication withsaid intake port and the other of said chambers being in directcommunication with said intake connection, said block and said valveplate having a first duct formed therein providing communication betweensaid crankcase and said other chamber and a second duct providingcommunication between said crankcase and said one chamber, said otherchamber being so arranged and constructed as to facilitate theseparation of oil from the refrigerant in the Working fluid enteringsaid compressor, the major portion of the working fluid flowin to saidintake portpassing through said restricted opening and the remainingportion passing through said ducts and said crankcase whereby oilseparated from the working fluid in said other chamber is trapped insaid crankcase.

6. A compressor comprising a cylinder block and a crankcase, said.cylinder block having a cylinder and a reciprocating piston mountedtherein, means including a rotating member having a crank pin thereonand a connecting rod between said crank pin and said pistontforreciprocating said piston, an oil splashing element secured to saidrotating member for directing oil to the working parts of saidcompressor, a valve plate having intake and exhaust ports for saidcylinder, valves for said ports, a head for said compressor havingintake and exhaust connections, said head having two chambers formedtherein and having a restricted opening providing communication betweensaid chambers, one of said chambers being in direct communication withsaid intake port and the other of said chambers being in directcommunication with said intake connection, said block and said valveplate having a first duct formed therein providing communication betweensaid crankcase and said other chamber and a second duct providingcommunication between said crankcase and said one chamber, an intaketube communicating with said second duct for conducting working fluid tosaid'second duct from said crankcase, said tube having its open endturned toward one side of said crankcase in the same direction as thatof the movement of said splashing element whereby the tendency to splashoil into said tube is minimized, said other chamber being so arrangedand constructed as to facilitate the separation of oil from therefrigerant in the working fluid entering said compressor, the majorportion 01' the working fluid flowing to said intake port passingthrough said restricted opening and the remaining portion passingthrough said ducts and said crankcase whereby oil separated from theworking fluid in said other chamber is trapped in said crankcase.

RALPH E. KING.

